Gr5 Titanium Wheel Bolts

Wheel bolts, as core load-bearing components connecting wheels to axles, have a direct impact on vehicle safety, handling, and stability. While traditional steel wheel bolts offer lower costs, they suffer from inherent drawbacks such as high density, susceptibility to corrosion, and limited fatigue life. These limitations make them difficult to meet the stringent requirements for lightweight, high-strength, and long-life components in high-end automobiles, racing cars, and specialized vehicles. Gr5 titanium wheel bolts, with their perfect balance of high strength and low density, exceptional corrosion resistance, and superior fatigue strength, have proven their reliability in the aerospace industry and are now being gradually introduced into the automotive, motorcycle, and bicycle markets.

Surface Treatment

Gr5 titanium inherently has excellent corrosion resistance, but surface treatment can further enhance its scratch and salt spray resistance while also meeting individual needs. Common surface treatments include:

Anodizing: The bolt acts as the anode and is placed in an electrolyte solution (such as sulfuric acid or oxalic acid). A direct current is applied to the bolt surface, forming an oxide film with a thickness of 5-20μm. This anodic oxide film not only enhances corrosion resistance but also allows for color control by adjusting the voltage (10-50V). For example, 10V produces silver, 30V produces blue, and 50V produces gold, meeting the personalized needs of the aftermarket.

Sandblasting: Diamond abrasive (80-120 mesh) is sprayed onto the bolt surface using a high-pressure airflow (0.5-0.8MPa) to create a uniform matte finish. Sandblasting removes scale and minor defects from the bolt surface, improving surface roughness (Ra 1.6-3.2μm), enhancing friction with the wheel hub, and preventing loosening after installation.

Passivation: For bolts that don’t require a colored appearance, nitric acid passivation can be used. This involves immersing the bolts in a 20%-30% nitric acid solution for 10-15 minutes to form a denser oxide film on the surface. This passivation treatment further improves the bolts’ salt spray resistance, allowing them to withstand over 1,000 hours in a salt spray test (neutral salt spray, GB/T 10125-2021), far exceeding the approximately 200 hours for steel bolts.